The present invention relates to vehicle suspension systems, and more particularly, to an automotive suspension system in which composite leaf springs are used in conjunction with an integral sway bar.
Vehicle suspension systems have heretofore included shock absorbers, springs (coil, leaf, air or torsion bar), axle housing, torque arms, A-frames, anti-roll bars, stabilizers, and so forth. These components have been assembled in various combinations to produce the desired ride and handling characteristics of the vehicle. In a typical suspension system, changes in the spacing between axles and the body/chassis are cushioned by springs. Spring vibration is limited by dampers which are usually called shock absorbers. The shock absorbers dissipate the energy stored in the springs by gradually forcing oil through orifices and valves. The flow resistance encountered by the oil results in compression and rebound forces which control the spring movement. The work done by the oil as it moves through the values converts energy stored in the springs into heat which is dissipated from the shock absorbers into the surrounding air.
There is a continuing effort to reduce the manufacturing cost of automobiles. There is also a continuing effort to increase the mileage of automobiles through weight reduction. Both of the aforementioned efforts must not unduly sacrifice performance or reliability. Conventional suspension systems tend to have numerous expensive heavy metal parts. It is therefore desirable to reduce the cost, weight and complexity of existing suspension systems.
Automobile suspensions systems have heretofore been provided which have incorporated composite leaf springs. See for example U.S. Pat. Nos. 4,540,197 and 4,557,500. These composite leaf springs have been constructed by molding glass or other reinforcing fibers and a resin or other binder into the desired shapes. Typically such composite leaf springs have been made of a plurality of laminations. They have been molded or otherwise constructed with a particular curvature so that they assume a desired configuration under normal loading conditions. Thus, these types of composite leaf springs are relatively complex and expensive to construct.
It would be desirable to provide a vehicle suspension incorporating less expensive and composite leaf springs. Such a suspension system would also preferably incorporate a sway bar to limit body roll during cornering.
U.S. Pat. Nos. 1,990,802 of Thompson; 2,559,105 of Banning, Jr., 3,142,598 of Rose; 3,456,939 of Duchemin; and 3,698,702 of Beck disclose other composite leaf constructions.
French Pat. No. 2,528,364 discloses twin fiberglass trailing arms for a rear wheel suspension. French Pat. No. 2,520,304 of Aubry disclose a transverse composite leaf spring arrangement.
Japanese Application No. 52-140771 discloses a leaf spring construction with metal and composite portions.
Swiss Pat. No. 305,921 discloses another transverse leaf spring suspension.
EPO Application No. 0 082 321 of Walter discloses another composite leaf spring construction.